The Receptor for Advanced Glycation Endproducts (RAGE) is a member of the immunoglobulin super family of cell surface molecules. Activation of RAGE in different tissues and organs leads to a number of pathophysiological consequences. RAGE has been implicated in a variety of conditions including: acute and chronic inflammation (Hofmann et al., Cell 97:889-901 (1999)), the development of diabetic late complications such as increased vascular permeability (Wautier et al., J. Clin. Invest. 97:238-243 (1995)), nephropathy (Teillet et al., J. Am. Soc. Nephrol. 11: 1488-1497 (2000)), atherosclerosis (Vlassara et. al., The Finnish Medical Society DUODECIM, Ann. Med. 28:419-426 (1996)), and retinopathy (Hammes et al., Diabetologia 42:603-607 (1999)). RAGE has also been implicated in Alzheimer's disease (Yan et al., Nature 382: 685-691, (1996)), erectile dysfunction, and in tumor invasion and metastasis (Taguchi et al., Nature 405: 354-357, (2000)).
Binding of ligands such as advanced glycation endproducts (AGEs), S100/calgranulin/EN-RAGE, β-amyloid, CML (Nε-Carboxymethyl lysine), and amphoteric to RAGE has been shown to modify expression of a variety of genes. For example, in many cell types interaction between RAGE and its ligands generates oxidative stress, which thereby results in activation of the free radical sensitive transcription factor NF-κB, and the activation of NF-κB regulated genes, such as the cytokines IL-1β, TNF-α, and the like. In addition, several other regulatory pathways, such as those involving p21 ras.
MAP kinases, ERK1 and ERK2, have been shown to be activated by binding of AGEs and other ligands to RAGE. In fact, transcription of RAGE itself is regulated at least in part by NF-κB. Thus, an ascending, and often detrimental, spiral is fueled by a positive feedback loop initiated by ligand binding. Antagonizing binding of physiological ligands to RAGE, therefore, is our target, for down-regulation of the pathophysiological changes brought about by excessive concentrations of AGEs and other ligands for RAGE.
Thus, there is a need for the development of compounds and pharmaceutical composition that antagonize binding of physiological ligands to RAGE.